Cryptocrystalline

Crypto meaning “hidden” refers to a rock texture in which individual crystals are too small to be distinguished even using a standard petrographic microscope. Crystals are typically less than a few μm in size – any smaller and the texture would be considered amorphousMaterial without the regular, ordered structure of crystalline solids. Amorphous substances, like glass, lack a definite repeating pattern in their atomic structures (crystallinity). There may be small regions of order, but, overall there is disorder.  . Among sedimentary terrestrial rocks, chert and flint are cryptocrystalline.

Cryptocrystalline (C) is one of the 8 types of chondruleRoughly spherical aggregate of coarse crystals formed from the rapid cooling and solidification of a melt at  ~1400 ° C. Large numbers of chondrules are found in all chondrites except for the CI group of carbonaceous chondrites. Chondrules are typically 0.5-2 mm in diameter and are usually composed of olivine textures as seen below.